Hormone treatments for uterine fibroids

The different hormone therapies include:

• GnRH agonists (injections or nasal sprays)
• GnRH antagonists (tablets)
• Progestins (hormonal intrauterine device and progestin-only pills)
• Combination of progestin and estrogen (combination pill)

The drug ulipristal acetate (trade name Esmya) was taken off the German market in 2024.

GnRH agonists are artificially produced hormones. They cause the ovaries to produce less of the natural hormone, estrogen, which helps to increase growth of the fibroids. When GnRH agonists are used to lower the level of estrogen, then the fibroids mostly stop growing, or can even shrink. Like other hormone-based medications, GnRH agonists may cause your period to stop altogether.

These hormones are usually injected under the skin or into muscle tissue once a month. They are also available in the form of depot (slow-release) injections that last for three months, and a nasal spray for daily use. GnRH agonists are only suitable for short-term treatment (up to six months).

During the treatment, it’s important to have the size of the fibroids checked by a doctor and keep an eye on whether your symptoms change. That also includes being aware of any side effects.

GnRH agonists make fibroids stop growing or shrink, which may reduce menstrual bleeding and period pain. If heavy periods have resulted in anemia, the treatment can improve it. But not all women benefit from these hormone analogues: About half don’t notice any improvement in their symptoms.

GnRH agonists are usually only used for less than six months. The goal is often to shrink the fibroids before a surgical procedure. The cuts on the womb that need to be made during surgery to remove the fibroids can be smaller too then. And if the fibroids are smaller, there is also less blood loss, and complications are less common than with larger fibroids.

Whether GnRH agonists are suitable depends on the type of fibroids and the planned surgical procedure. Studies show that they have benefits when used before myomectomy (removal of the fibroids) or hysterectomy (removal of the womb). GnRH analogues don’t have any advantages if fibroids located directly under the lining of the womb are removed during hysteroscopy (use of a narrow telescope to see inside the womb).

Estrogen deficiency related to the use of GnRH agonists can lead to some distressing problems. The medications often cause side effects that are very similar to problems associated with menopause. More than half of women who use them experience hot flashes, sweating, headaches or vaginal infections.

GnRH agonists can increase the risk of osteoporosis (loss of bone mass) if they are used for longer than one year. Because of their side effects, they aren’t suitable for long-term use.

GnRH antagonists reduce the amount of reproductive hormones secreted by the pituitary gland at the base of the brain. So far, only one GnRH antagonist has been approved for the treatment of fibroids in Germany. It is a combination of the drugs relugolix, estradiol and norethindrone acetate (brand names: Ryeqo, Myfembree).

The combination drug is taken every day in the form of a tablet. It can be used over a longer period of time than GnRH agonists can. GnRH antagonists can also make your periods stop altogether.

In two studies involving about 250 women:

• 7 out of 100 women who took a fake medication (placebo) had a weaker period.
• 70 out of 100 women who took the relugolix/estradiol/norethindrone acetate had a weaker period.

The symptoms also improved generally, the pain went away and quality of life increased.

The possible side effects include headaches, hot flashes and spotting (vaginal bleeding between periods). The drug is usually well tolerated, though: Only few women stop using the treatment because of side effects.

A hormonal coil is placed inside the womb, and can be left there for 3 to 8 years. Also known as intrauterine devices, they are normally used for contraception. They continuously release artificial hormones called progestins, which are similar to the female sex hormone progesterone. Progesterone prevents the lining of the womb (endometrium) from building up during the menstrual cycle.

Hormonal IUDs are only suitable for treating fibroids that aren’t too big. Larger fibroids may change the shape of the womb, making it impossible to insert an IUD.

IUDs can’t reduce the size of the fibroids, so they won’t relieve symptoms like pain and cramps. Because the hormones keep the lining of the womb from growing back, menstrual periods are often weaker or go away completely. This way IUDs can lower the amount of blood lost during menstruation and prevent anemia.

It can help to keep a diary when starting treatment so that you can keep track of things like how often you still have heavy periods, whether other symptoms improve or whether you experience any side effects. These notes can help your doctor to assess how effective the treatment is.

Hormonal IUDs may cause various side effects, including acne, spotting, mood swings and breast tenderness. These kinds of side effects are usually more common during the first few months of treatment. An IUD may slip from its position or be pushed out. This happens in about 50 out of 1,000 women within five years. Inserting a hormonal IUD carries a certain risk: It is estimated that about 1 out of 1,000 women injure the whom while doing so.

Birth control pills (“the pill”) contain either a combination of estrogen and progestin (combination pill), or only progestin (mini-pill). Progestin is a synthetic version of progesterone. Both kinds can reduce the flow of menstrual blood, so they are an option for women who have heavy periods. It is not clear how effective the pill is in relieving fibroid symptoms, or how it compares to other treatments, though. This subject is poorly studied in general, and there is a lack of good-quality research.

If you take the combination pill regularly, over time you will usually not have a period. Because using the pill in this way – with only rare breaks or none at all – Because this way of using the pill hasn’t been approved in Germany, it is considered to be “off-label use” (non-approved use). As a result, some public health insurers in Germany may not cover the costs.

The pill may cause side effects such as water retention, headaches and breast tenderness. It can also increase the risk of blood clots (thrombosis), especially in older women and women who smoke.